Research Article Open Access

Identification a Novel Raw-Starch-Degrading-α-Amylase from a Tropical Marine Bacterium

Zeily Nurachman1, Alfredo Kono1, Ocky Karna Radjasa2 and Dessy Natalia1
  • 1 Institute Technology Bandung, Indonesia
  • 2 Diponegoro University, Indonesia

Abstract

Problem statement: Bacteria from the surface of the tropical marine hard coral Acropora sp. were screened for producing raw-starch-degrading-α-amylase. Approach: Based on its 16s rDNA sequence, a bacterium that produced the highest amylolitic activity was identified as Bacillus amyloliquifaciens ABBD. The bacterial isolate secreted a α-amylase extracellularly and then the enzyme was partially purified by ammonium sulfate precipitation followed by anion exchange chromatography. Results: Electrophoresis results both SDS-PAGE and native PAGE suggested that the enzyme was a heterodimeric protein (97 kDa) consisting of 45 and 55 kDa subunits. The α-amylase had an optimum pH of 7.0 and temperature of 60°C. More than 80% activity of the enzyme was retained under high salt conditions (up to 20% NaCl). The enzyme remained stable at 50°C for 1 h. Starch hydrolysis by the enzyme at 70°C yielded oligosaccharides (G2-G4) and at room temperature yielded glucose/maltose (G1 and G2). Conclusion: The B. amyloliquifaciens ABBD α-amylase was capable of degrading various raw starch granules from corn, rice, cassava and sago at room temperature.

American Journal of Biochemistry and Biotechnology
Volume 6 No. 4, 2010, 300-306

DOI: https://doi.org/10.3844/ajbbsp.2010.300.306

Submitted On: 28 October 2010 Published On: 31 December 2010

How to Cite: Nurachman, Z., Kono, A., Radjasa, O. K. & Natalia, D. (2010). Identification a Novel Raw-Starch-Degrading-α-Amylase from a Tropical Marine Bacterium. American Journal of Biochemistry and Biotechnology, 6(4), 300-306. https://doi.org/10.3844/ajbbsp.2010.300.306

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Keywords

  • α-amylase
  • amylolytic enzymes
  • Bacillus amyloliquifaciens
  • C-terminal domain
  • Glycosyl Hydrolase (GH)
  • hard coral Acropora sp.
  • marine bacterium
  • Marine Broth (MB)
  • Thin Layer Chromatography (TLC)
  • yielded oligosaccharides